Lamp-focus-securing device



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LAMP FOCUS SECURING DEVICE Filed Dec. 12, 192'( lltaltented et. m, imm

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LAMlP-FUC'US-SECURTNG IDEVTE.

application tiled December la, 192'?.

This invention relates to a device l'or preventing lamps from getting out oit tocusat-er having been properly set. The invention is particularly designed tor use on the headt lights of automobiles and in similar places where the lamp is tocused by moving it for ward and back along the anis ot a mirror by means ot a screw.

The principal object ot the invention is to l provide means whereby, when said screw is turned to the proper position, it can be tastened up in a very simple way and will not thereafter be unscrewed by the jars and jolts to which the structure is subjected and also to provide this means in a very simple and inexpensive form and without the addition olf expensive parts.

Reference is to be had to the accompanying drawings in which Fig. 1 is a central sectional view of a head light of an automobile with a preferred embodiment ot this invention applied thereto, and

Fig. 2 is a similar view ot the central parts all on enlarged scale.

As is well understood the lamp socket 10 is held and guided in a cylindrical guide 11 at the rear of a mirror 12 and located along the axis thereof. The lamp 13 mounted in a@ the socket is adapted to be adjusted back and forth along the axis of the mirror to get it into proper tocus. This is done by a screw 141-. entering a screw-threaded projection 15 on the socket.

Usually this screw has been provided with a head on the outside ot the headlight casing and it is turned to the proper position to getthe lamp focused and leit there.

The j olting oic the car tends to turn the screw .im which has the etl'ect ot' unscrewing it from the projection 15.` @rdinarily there is nothing to prevent this and lamps get out of focus very rapidly alter having been adjusted.

For the purpose ot positively preventing i5 'the unscrewing oit the screw 14: we provide it with a lined integral collar 16 which rests against the inner side of the casing 2O and is pressed thereagainst by a spring 17 which bears at the other end on the projection 15.

We also provide the screw 111 with a reduced integral end 18 extending` through an opening in the back of the casing 20 and provided with a lett handed screw thread.

Elli

Serial No. 239,332.

@n the lett handed screw thread is placed a nut 19.

lin the use ot the device the screw 14; is turned in the usual way by inserting a screw driver in the slotted end ot' the screw eX- posed at the back ot' the lamp casing. @t course, the collar 16 always remains back against the casing 2O and the spring 17 tends to torce the socket 10 as t'ar forward as possible. The lamp having been adjusted to the proper position the nut 19 is put on and turned up firmly against the casing 20 at the rear.

Tt is obvious that the vibrations of the car cannot have any continuous or permanent effect on the adjustment of the parts except by unscrewing the screw 14 in the passage of the projection 15. But when the screw turns in that direction it necessarily tightens up the nut 19 in the lett handed screw 18 and stops the unscrewing of the screw 14 when it commences.

Therefore the lamp will remain in focus and under ordinary usage will not get out of tocus at any time. This constitutes a very simple and inexpensive way of preventing the diiliculty herein mentioned, involves no expensive parts and there is nothing that is likely to get out of order in use.

Although we have illustrated and described only one torni of the invention we are aware of the fact that modications can be made therein by any person skilled in the art without departing trom the scope of the invention as expressed in the claims.

Therefore, we do not wish to be limited in these respects but what we do claim is 1. ln a headlight, the combination with a lamp casing, a rei-lector, a' lamp socket and a guide therefor, ot a screw connected with the socket tor moving the socket tor adjustnient relative to said reflector, a collar inha tegrally mounted on the screw, a spring on the screw exerting opposite forces on the socket and collar to torce the collar against the lamp casing, said screw having a lett handed screw portion ot reduced diameter 10o on its end beyond the collar, projecting through the back of the casing, a nut on the lett handed screw portion to prevent the adjusting screw from unscrcwing, and means on said screw whereby saine may be turned. loa

2. Tn a light, having a casing and a reflecdit tor, the combination With a lamp socket and ing screw from unserewing, and means on a guide therefor, of a screw connected With said screw whereby same may be turned. 10 the socket for adjusting saine relativeI to In testimony whereof we have hereunto af- 4Said reflector, va coll-ar on the screw, adapted iXed our signatures.

5 yto abut said casing, said screw having a left handed Screw portion projecting through the ISIDORE L. DUQUETTE. hack of the casing, and a nut on the left VIL'FRED J. PLASSE. handed screw portion to prevent the adjust- CHARLES A. MERRILL. 

